Pump



I Dec. 19, 1933.. J, A, TENNANT PUMP Filed Nov. 4, 1932 INVENTOR.

ATTORNEY.

the barrel when PatenteclDec. '19, 1933 PUMP Joseph A.

Delaware Tennant, Houston, mesne assignments, to pany, Round Rock, Tex.,

Tex., assignor, by Stephens Pump Coma corporation of ApplicationNovember 4, 1932. Serial No. 641,201 7 Claims. (Cl. 103-44) Thisinvention relates to pumps.

, It will be. found particularly useful in pumps designed for pumpingabrasive and corrosive fluid of the general type disclosed by LettersPatent of the United States to Stephens No. 1,848,441, of March 8, 1932.A conventional pump of this type, adapted for use as a mud or slush pumpin deep well drilling, includes a barrel; inlet and outlet valvetherefor; a hollow expansible member within the barrel; and areciprocable piston to actuate fluid confined within the expansiblemember to cause expansion and contraction thereof, whereby fluid isdrawn into and forced out of said barrel.

It is important that there be as little clearance as possible betweenthe expansible member and the expansible member is expanded so thatpractically all of the gas and fluid in the barrel will be forced outthrough the outlet valve. This is important because when the expansiblemember is contracted it tends to create a vacuum in the barrel and it isthis that draws fluid into the barrel through the inlet valve, and allgas then present in the barrel expands and occupies a part of the volumein the barrel that should be occupied by incoming fluid.

Reduced clearance can be obtained only by ex pending the hollowexpansible member substantially to the walls of the barrel. This cannotbe done safely if, for instance, the expansion takes place firstadjacent the outlet port because the outlet port will be thereby sealedofi and the adjacent portion of the member will be pushed therethroughand ruptured.

The present invention has for its object the provision of a new andimportant expansible member for pumps of this type, whereby the saidclearance will be greatly reduced without any objectionable results.This is accomplished by so constructing the member that expansionthereof starts at that end of the barrel remote from the outlet port andproceeds along the barrel toward the outlet port; the member, whencompletely expanded, being in contact with substantially the entireinner surface of the barrel.

The preferred embodiment of the pumping member in a pump of this type isshown by the accompanying drawing of which Fig. 1 is a fragmentarysectional elevation and Fig. 2 a vertical section on the line 2 -2 ofFig. 1.

In the drawing the barrel is indicated at 1. It has in its upper portionadjacent one end an outlet 2 normally closed by an outlet valve 3. Inthe lower portion of the barrel is an in et 4 normally closed by aninlet valve 5.

' the barrel 1 and the clamp A piston 6 extends through the clamp '7 andis packed as indicated at 8.

The new and improved expansible member provided by this invention isindicated at 9.

It has on one end an external annular flange l0 compressed by and heldbetween one end of l which is secured to the barrel by bolts 11; and atthe other end an internal annular flange 12 compressed by and heldbetween the other end of the barrel 1 and the clamp 13 which is securedto the barrel by bolts 14. The ends of the expansible member 9 arethereby connected and sealed to the ends of the barrel 1.

The member 9- is preferably substantially cylindrical and made ofrubber, increasing in thickness from that end of said barrel 1 remotefrom the outlet 2 toward that end ofsaid barrel adjacent the outlet2 sothat the resistance to expansion offered by the member 9 increaseslongitudinally toward the outlet means.

When the piston 6 is moved on its forward stroke (to the left, Fig. l)the expansible member 9 is expanded by the displacement of the actuatingfluid therein. As the member 9 increases in thickness longitudinallyfrom that portion remote from the outlet 2 toward the outlet 2 it willoffer a resistance to expansion increasing longitudinally toward theoutlet port 2. Therefore, the expansion of the member 9 will start atits said remote portion and will then proceed along the barrel towardthe outlet port '2. The construction is such that the member 9 movessubstantially into contact with the entire inner surface of the barrel 1and therefore practically all of the gas and fluid in the barrel isexpelled through the outlet port 2.

The invention is not limited to the preferred embodiment and use hereindisclosed.

I claim:

1. A hollow expansible pumping member constructed to offer alongitudinally increasing resistance to expansion.

2. A hollow expansible pumping member constructed to offer alongitudinally and gradually increasing resistance to expansion fromsubstantially one end to the other.

3.- A hollow expansible pumping member increasing in thicknesslongitudinally to offer a varying resistance to expansion.

4. A substantially cylindrical hollow rubber pumping member increasingin 'thiclmess-longb tudinally to offer a varying resistance toexpansion.

5. A pump having a barrel; inlet and outlet 110 barrel through saidinlet means and to expel it from said barrel through said outlet means;said member being so constructed that, when expanded, it moves firstsubstantially to that portion of the inner surface of said barrel remotefrom said outlet means and then toward said outlet means.

7. A pump having a barrel; inlet and outlet means for said barrel; saidoutlet means being adjacent one end of said barrel; a hollow rubberpumping member in said barrel; and means to contract and expand saidmember to draw fluid into said barrel through said inlet means and toexpel it from said barrel through said outlet means; said memberincreasing in thickness substantially from that end of said barrelremote from said outlet means to that end of said barrel adjacent saidoutlet means to ofier a resistance to expansion increasing longitudinaly toward said outlet means.

JOSEPH A. TENNANT.

